The use of amine oxide detergent surfactants in cleaning compositions is well known. Amine oxides are most commonly used as cosurfactants to boost and maintain suds formation in laundry, shampoo, and dishwashing detergent compositions. Amine oxides have occasionally been used in hard surface cleaners such as acidic toilet bowl cleaners (pH of 2 or less), dishwashing liquids containing occlusive emollients (pH of 4 to 6.9), and selected non-acidic (neutral to alkaline) hard surface cleaners. In conventional non-acidic hard surface cleaners, amine oxide detergent surfactants are generally non-ionic (pK.sub.a between about 4 and about 6).
Amine oxide detergent surfactants have been used in compositions which also comprise amine buffering agents. Cripe et al., U.S. Pat. No. 5,376,310, and Ofosu-Asante, U.S. Pat. No. 5,378,409, both disclose alkyl ethoxy carboxylate-containing dishwashing compositions which may comprise amine oxide suds boosters and amine buffering agents; both references teach that the pK.sub.a of the buffering agent is about 0.5 to about 1.0 units below the pH of the composition. Fu, WO 92/06157, discloses detergent compositions comprising an alkyl ethoxy carboxylate component and a polyhydroxy fatty acid amide component, which compositions may further comprise amine oxide suds boosters and amine buffering agents. Kokx et al., GB 2,123,847, disclose detergent compositions containing amine oxide which have a reserve alkalinity of greater than about 2.5; Kokx et al. also teach that the compositions preferably contain free monoethanolamine to provide the reserve alkalinity. None of these references teach that the amine is protonated.
These nonionic amine oxides provide good cleaning properties and leave little or no visible residue on hard surfaces when they dry. Unfortunately, non-acidic hard surface cleaners containing amine oxides typically stain or discolor vinyl (e.g., polyvinyl chloride) surfaces. The staining amounts to a light yellow to dark brown discoloration of the vinyl. Staining will also occur on waxed vinyl surfaces where areas of wax are worn thin or are chipped away so that the amine oxide can come in direct contact with the vinyl.
Thus, many prior art non-acidic amine oxide compositions are limited in that the compositions stain vinyl surfaces. Additionally, many prior art amine oxide compositions are limited in that they also contain high levels of anionic compounds or salts thereof, such compositions can leave behind residues and therefore are undesirable for no-rinse applications. Also high level of anionic compounds can cause quaternary disinfectants to precipitate.